System and method for mediating transactions of digital documents

1. A method for converting a first transaction document to a second transaction document comprising: receiving from a first user a first transaction document having a first format; converting said first transaction document into an intermediate document having a unified internal format, said conversion being based at least in part on a first set of rules associated with said first user, wherein converting said first transaction document into said intermediate document comprises retrieving for inclusion in said intermediate document data from a source other than said first document; selecting based on data obtained from said intermediate document a second user, said second user being an intended recipient of said first transaction document; validating data in said intermediate document based at least in part on validation rules associated with said second user, wherein said validating comprises correcting errors in said intermediate document based on said validation rules associated with said second user; converting data in said intermediate document into a second transaction document having a second format based on rules associated with said second user; and sending said second transaction document to said second user.

2. A method for converting a first transaction document to a second transaction document comprising: receiving from a first user a first transaction document having a first format; converting said first transaction document into an intermediate document having a unified internal format, said conversion being based at least in part on a first set of rules associated with said first user, wherein converting said first transaction document into said intermediate document comprises retrieving for inclusion in said intermediate document data from a source other than said first document, wherein said retrieving data for inclusion in said intermediate document comprises executing web-services; selecting based on data obtained from said intermediate document a second user, said second user being an intended recipient of said first transaction document; validating data in said intermediate document based at least in part on validation rules associated with said second user; converting data in said intermediate document into a second transaction document having a second format based on rules associated with said second user; and sending said second transaction document to said second user.